Self-laying track



Oct. 4, 1949. c. F. BALL SELF-LAYIHG TRACK 2 Shams-Sheet l Filed Jan. 6, 1945 IN VEN TOR. m d. M BY @my ,WM-(F Lv n r ron/ve Ys.

Oct. 4, 1949. c. F. BALL 2,483,961

SELF-LAYING TRACK Filed Jan. 6. 1945 2 SheetsSheet 2 gnu-551.5145.. @M101 YJ la Wurz... LJ- arme/mm.

Patented Oct. 4, i949 UNITED STATES PATENT OFFCE Manufacturing Company, Franklin Pa., a corporation o! Pennsylvania Application January 8, 1945, Serial No. 571,638

16 Claims. (Cl. 305-10) This invention relates to endless sell-laying tracks such as used on tractors and self-propelled mining machinery.

In the mining of coal, for example, seams often are encountered that are very thin, perhaps not over thirty inches thick. In mechanized coal mines it becomes difllcult or impossible' to move ordinary coal loading machines into the thin seams. Therefore, attempts continually are being made to make such loading machines lower so that they can operate in thinner seams. The diiliculty. however, is that there are length and breadth limitations for the machine, so it must be made high enough to provide the space required for housing the apparatus and equipment necessary for operating the machine. 1n an eiort to reduce the height oi the machine, some ci this apparatus even has been mounted between the upper and lower reaches of the selflaying trackwith which the machine is provided on each side. The space taken by such apparatus between the reaches o! the track, plus the thickness of the track above and below this space. determines the minimum height that the machine can have.

It is an object of this invention to provide an endless self-laying track which is carried by double sprockets or wheels; in which the distance between its upper and lower surfaces is reduced without reducing the maximum spacing between the inner surfaces of its upper and lower reaches, and in which a maximum distance is provided between the axis oi' ech pair of sprockets and the inner surface oi the track traveling around them. Other objects are to provide such a track which is i'ormed to prevent jamming oi foreign objects between its shoes or between the track and the sprockets that carry it, in which the shoes are strong and durable as well as being simple in design, and in which the manner of making the holes i'or the pivot pins is improved.

In accordance with this invention an endless self-laying track is supported by sprockets connected to a vehicle or machine that the track is to propel along the ground. This track is formed from a plurality oi shoes that are pivotally connected together in end to end relation with their adjacent ends disposed close together so that large foreign objects can not catch between them. Each shoe is formed in one piece, such as by casting or forging, but it is in the form of a pair of laterally spaced parallel chain links rigidly held apart by a suitable intermediate member. preferably in the form of a tread plate.

The opposite ends ci the links are provided with transverse openings through which pintles extend for pivoting the shoes together. The tread plate has its outer surface substantially in the plane oi the outer surfaces of the links. but the plate is considerably thinner than the adjoining portions of the links so that a fairly deep channel is formed between the links. 'I'he plate has an inner plane surface, that is, a relatively smooth suriace unobstructed by projections. The channels thus formed along the upper and lower lengths of the track permit those lengths to be positioned closer together than otherwise, because the apparatus located between them can project into the channels. This reduces the thickness of the track above and below that apparatus, whereby the overall height o! the track is reduced in cases where inches count. The outer surfaces of either the links or the tread plates may be provided with traction lugs. The central portions of the links are provided with recesses for receiving the teeth of the sprockets, and one side of each recess is open so that coal or stones can be pushed out of it laterally as a tooth enters the recess. Ii the foreign object is caught between the end of the tooth and the link, it is pushed out of the recess through a hole extending outwardly through the link from the recess. In this way stones and dust particles are prevented from jamming the track or grinding up in it.

The invention is illustrated in the accompanying drawings in which Fig. 1 is a side view of my self-laying track mounted on a pair of sprockets; Fig. 2 is an enlarged vertical section taken on the line II-II of Pig. 1; Fig. 3 is a plan view of the inner surface ci one of the shoes; Fig. 4 is a vertical section through the shoe taken on the line IV-IV of Fig. 3; Fig. 5 is a side view ci the shoe: Figs. 6 and 'l' are vertical sections through the shoe taken on the lines VI-VI and VII-VII, respectively, of Fig. 3; and Fis. 8 is a fragmentary horizontal section through a track drive.

Referring to Figs. 1 and 2 oi the drawings, my self-laying track I is shown extending around two pairs of horizontally spaced sprockets 2, one or both pairs ci which may be driven. These sprockets are connected to one side of a vehicle or a self-propelled machine, such as a mine loading machine (not shown). Another set oi sprockets carrying a like track are mounted on the opposite side of the vehicle or machine in the customary manner. In order to make the machine as low as possible, some of the apparatus that must be carried by it in order for it to operate is mounted in the space at each side of the machine bounded by the sprockets and the upper and lower reaches of the endless track. This apparatus (not shown) may be mounted in a housing or box 3 that is rigidly supported in any suitable manner from the frame of the machine. Secured to the bottom of the box is a plate 4 against which the lower length of the track bears and along which it slides, a1- though rollers may be substituted for this plate if desired.

It is a feature of this invention that the overall height of the track is reduced without reduein the height of the box, which is presumed to be as small as possible for the apparatus it must house. Accordingly, each track shoe 8 is formed in one piece, and, as shown in Fig. 3, has the form and appearance of a pair oi' laterally spaced parallel chain links 1 connected together opposite each other by a rectangular tread plate 8 integral therewith. One end of each link is bifurcated and is provided with a pair of axially-aligned transverse openings 9 and IU for receiving a two diameter pintle II (Figs. 2 and 4) by which the link is pivotally connected to the opposite end of the next link. In order that the pintle may have a drive iit with the forked end of the link, opening 9 has a. diameter slightly less than opening I0. This can be accomplished by a two diameter reamer, only the smaller secton of which is used to form the inner opening. Also, the inner endand central portion oi the pintle is just enough smaller than the outer opening I8 to permit the major portion of the pin to be passed through the outer opening. The inner and outer end portions of the pin are slightly larger than the inner and outer openings, respectively, so that those portions o! the pin have a drive nt with both openings. The tongue-like end of each link, which projects into the fork of the adjoining link, is provided with a transverse opening I2 through which one of the pintles II extends. This opening has the same diameter as outer opening I0, and may be made by the same reamer, whereby the formation of openings 9, III and I2 is facilitated. The perforated ends of the links are so shaped that connected links do not spread apart when they pass around the sprockets and allow foreign objects to catch between their adjoining ends. Also, by forming the opposite ends of each tread plate with the same radius and making them concentric with the adjacent pintle, adjoining tread plates do not spread apart when they are carried around the sprockets.

The inner surface of each link is provided centrally with a recess I3 for receiving a sprocket tooth so that the shoe will be carried around the sprocket. As shown in Figs. 2. 4 and 5, the side of this recess adjacent the outer surface of the sprocket is open so that foreign objects. such as stones or coal, can be pushed laterally out of the recess by the sprocket tooth. This prevents such objects from jamming the track or crushing between the track and sprockets and thus rapidly wearing them. In case such an object is caught between the end of the tooth and the link, so that it can not be pushed laterally out ci recess I3, it is forced out of the recess through an opening i4 connecting the recess with the outside of the track. Also, this opening prevents dust and small particles from packing in the recess.

The tread plate B, which connects the two links of each shoe, preferably has an outer surface lying in the plane of the outer surfaces of the adjoining links, as shown in Fig. 4. The entire outer surface ot the shoe thus is dat except for the usual traction lugs Il which may project from the outer surface of the shoe. The tread plate is materially thinner than the links, most suitably being less than half as thick. The result, as shown in Fis. 4. is that a channel I1 is formed along the inside of the shoe the links forming the side iianges of the channel and the tread plate the connecting web. The tread plate has an inner plane surface, by which is meant a surface that is not interrupted by projections that would obstruct the channel. The plate's inner surface substantially coincides with the pitch line of the link; i. e. a line connecting the axes o! pintle openings 9 and I2, whereby the tread plate is located close to that line and the nut-cracker action between the ends of adjacent plates thereby held to a minimum. The tread plate adds strength to the chains, but need be only thick enough to resist bending of itself. The adjacent sides of the two links of each shoe are straight, and their lines of junction with the tread plate are parallel, and such sides are also parallel to a straight line midway between them, and they form side flanges for the channel which extend parallel with each other.

The channels Il. when placed end to end, form around the inside of the track a continuous channel into which the marginal portion of box 3 can project so that the thickness of track projecting above and below the box is reduced to the thickness of the relatively thin tread plates which do not project beyond the outer surfaces of the links. This permits coal loading machines to be used in thinner seams than before.

As shown in the arrangement disclosed in Fig. 8. this track is especially suitable for use with double sprockets 2U that are driven by a drive sprocket 2i rigidly mounted between them on their common shaft 22. The drive sprocket is driven by a chain 23 from a small sprocket 24 mounted on a drive shaft 26 projecting between the upper and lower lengths oi the track t. A box or housing 21. supported from the frame of the machine, carries bearings 28 that support shaft 22, and also encloses the large and small driving sprockets and the chain connecting them. Because of the channels Il in the track shoes, housing 2l can project into the shoes and thus provide greater clearance between shaft 22 and the portion of the housing wall extending around it. This makes is possible to use a larger drive sprocket 2 I.

According to the provisions of the patent statutes, I have explained the principle and construction of my invention and have illustrated and described what I now consider to represent its best embodiment. However, I desire to have it understood that, within the scope of the appended claims, the invention may be practiced otherwise than as specifically illustrated and described.

I claim:

l. A self-laying track formed from a plurality of integrally formed shoes pivotally connected together end to end, each shoe comprising a pair of laterally spaced parallel chain links provided at their ends with transverse pintle-receiving openings, and a tread plate connecting said links and having its outer surface substantially in the plane of the outer surfaces of the links, said plate having an inner plane surface and being considerably thinner than the adjoining portions of the links whereby a channel is formed between them, said links having junctions with said tread plate which extend parallel with each other longitudinally of the shoe, and said links themselves being straight along such junctions and forming straight side flanges for the channel.

2. A self-laying track formed from a plurality of integrally formed shoes pivotally connected together end to end. each shoe comprising a pair of laterally spaced parallel chain links provided at their ends with transverse pintle-recelving openings, the central portion of each link being provided with a sprocket tooth receiving opening, and a tread plate connecting said links and having its outer surface substantially in the plane of the outer surfaces of the links, said plate having an inner flat plane surface and being considerably thinner than the adjoining portions of the links whereby a channel is formed between them, the inner sides of the portions of the links connected with said tread plate being straight and forming side flanges for the channel which extend, longitudinally of the shoe, parallel with each other.

3. A self-laying track formed from a plurality of integrally formed shoes pivotally connected together end to end, each shoe comprising a pair of laterally spaced parallel chain links provided at their ends with transverse pintle-receiving openings, the central portion of each link being provided with a sprocket tooth receiving recess having an open side, and a tread plate connecting said links and having its outer surface substantially in the plane of the outer surfaces of the links, said plate having an inner plane surface and being considerably thinner than the adjoining portions of the links whereby a channel is formed between them.

4. A self-laying track formed from a plurality of integrally formed shoes pivotally connected together end to end, each shoe comprising a pair of laterally spaced parallel chain links provided at their ends with transverse pintle-receiving openings, the central portion of each link being provided with a sprocket tooth receiving recess having an open side. and a rigid member spacing said links a fixed distance apart.

5. A self-laying track formed from a plurality of integrally formed shoes pivotally connected together end to end, each shoe comprising a pair of laterally spaced parallel chain links provided at their ends with transverse plntle-receiving openings, and a tread plate connecting said links and having its outer surface substantially in the plane of the outer surfaces of the links, one free edge of the plate being iiush with the adjoining ends of the links, the opposite edge ofnthe plate being disposed inwardly relative to the plntlereceiving openings in the adjacent ends of the links, and said plate having an inner plane surface and being considerably thinner than the adjoining portions oi the links whereby a channel is formed between them, said links having the portions thereof adjoining said plate uniformly spaced from end to end and all other portions thereof spaced by at least as great a distance whereby a continuous uniform unobstructed channel is provided extending from shoe to shoe.

6. A self-laying track formed from a plurality of integrally formed shoes pivotally connected together end to end, each shoe comprising a pair of laterally spaced parallel chain links provided at their ends with transverse plntle-receiving openings, the central portion of each link being provided with a sprocket tooth receiving recess having an open side, said central portion also being provided withan opening extending outwardly therethrough from said recess, traction lugs projecting from the outer surfaces of said links, and a tread plate connecting said links and having an outer plane surface in the plane of the outer surfaces oi the links, said plate having an inner plane surface and being considerably thinner than the adjoining portions of the links whereby a channel is formed between them.

7. A shoe adapted to be pivotally connected to similar shoes in a self-laying endless track traveling around sprockets, said shoe comprising a pair of laterally spaced parallel chain links provided at their ends with transverse pintle-receiving openings, and a tread plate connecting said links and having an inner ilat plane surface substantially coinciding with the pitch line of the shoe, whereby a channel is formed between the links, said plane surface of the tread plate being adapted to bear against a supporting member between the lower portions of the sprockets.

8, In combination, two pairs of laterally spaced sprockets, a self-laying track extending around said sprockets and formed from a plurality of integrally formed shoes pivotally connected together along their opposite sides, the inner surface of said track being provided with a channel extending lengthwise thereof, and a box mounted between the upper and lower lengths of the track and projecting into said channel.

9. In combination, a pair of laterally spaced coaxial sprockets, means between said sprockets for driving them, and a self-laying track extending part way around said sprockets and formed from a plurality of integrally formed shoes pivotally connected together along their opposite sides, the inner surface of the track being provided with a channel extending lengthwise thereof and part way around said driving means, whereby said driving means is protected by said sprockets and track.

l0. A shoe adapted to be pivotally connected to similar shoes in a self-laying endless track. said shoe comprising a pair of laterally spaced parallel chain links bifurcated at one end and provided with a tongue at the opposite end, the tongue and the outer fork of the blfurcated end of each link being provided with transverse openings therethrough of substantially the same diameter, the inner fork of each of said bifurcated links being provided with an opening axially aligned with said opening in the outer fork but having a smaller diameter, a pintle disposed in said fork openings and having a driving fit with both of them, the central portion of the pintle between said i'orks being substantially the same size as its inner end portion, and a tread plate connecting said links.

11. A self-laying track formed from a plurality o! integrally formed shoes pivotaliy connected together end to end, each shoe comprising a pair of laterally spaced parallel chain links provided at their ends with transverse pintle-receiving openings, the central portion of each link being provided with a sprocket tooth receiving recess, traction lugs projecting from the outer surfaces of said links, and a tread plate connecting said links and having an outer plane surface in the plane of the outer surfaces of the links. said plate having an inner plane surface and being considerably thinner than the adjoining portions of the links whereby a channel is formed between them.

l2. In combination, a pair of laterally spaced coaxial track sprockets. a driving sprocket between said track sprockets for driving them. said driving sprocket being nearly as large as the track sprockets, and a self-laying track extending part way around the track sprockets and formed from a plurality of integrally formed shoes pivotally connected together along their opposite sides, the inner surface of the track being provided with a channel extending lengthwise thereof and part way around said driving sprocket, whereby the driving sprocket is protected by the track sprockets and the track.

13. A shoe adapted to be pivotally connected to similar shoes in a self-laying endless track, said shoe comprising a pair of laterally spaced parallel chain links each having a body portion and a projecting tongue portion and having its body portion provided with an end slot to receive a tongue portion of another link, said slotted body portion and said tongue portion having transverse pintle-receiving openings, and a tread plate connecting the body portions of said links and having its outer surface substantially in the plane of the outer surfaces of the links, said plate having an inner plane surface and being considerably thinner than the body portions oi.' the links whereby a channel is formed between them. said projecting tongue portions having all portions thereof outside the lines, extended, of the lateral sides of said inner plane surface, whereby an unobstructed channel of substantial width may extend from said shoe to an adjacent shoe.

14. A self-laying track formed from a plurality of integrally formed shoes plvotally connected together end to end, each shoe comprising a pair of laterally spaced parallel chain links each in the form of a body bifurcated at one end and having a projecting portion at its other end for reception in the biiurcated end of another link, said bifurcated end and said projecting portion traversed by transverse pintel-receiving openings, and a tread plate connecting the bodies of said links and having its outer surface substantially in the plane of the outer surfaces of the links, said plate having an inner plane surface and being considerably thinner than the adjoining portions of the links whereby a channel is formed between the links. the inner sides of the bodies of said two links being straight and being parallel to a straight line mid- Y way between them and forming parallel sides for the channel and said projecting portions lying outside the side walls of said channel extended.

15. A shoe adapted to be pivotaliy connected to similar shoes in a self-laying, endless track. said shoe comprising a tread plate having an outer plane surface and an inner plane surface and adjacent its opposite side edges integral upstandlng portions including at each side a forked portion, a perforated ear portion and an inter mediate portion having a. sprocket tooth receiving opening, said upstanding portions and said plate cooperating to form a channeled element having throughout the length of said plate an unobstructed channel of at least substantially uniform width.

16. A shoe adapted to be pivotally connected to similar shoes in a self-laying endless track, said shoe comprising a pair oi laterally spaced parallel portions provided at their ends with transverse pintle-receiving openings and a tread plate connecting said parallel portions and having its outer surface substantially in the plane of the outer surfaces of said laterally spaced parallel portions, said plate having an inner surface extending between said spaced parallel portions and being considerably thinner than the latter throughout its whole extent between its junctions with said spaced parallel portions, whereby a clear and unobstructed channel extends between said portions, each of said spaced parallel portions having a sprocket tooth receiving recess opening through its surface more remote from said tread plate and also through a lateral side thereof.

CHARLES F. BALL.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,148,518 Krupp Aug. 3, 1915 1,450,471 Wickersham Apr. 3, 1923 1,513,459 Jett Oct. 28, 1924 1,759,049 Fykse May 20, 1930 1,947,883 Snyder Feb. 20, 1931i 

